Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule Of Income Taxes [Line Items]
Valuation allowance on deferred tax assets	$ 0
Income tax benefits related to stock options credit to additional paid-in captial	1,121,000	3,519,000	3,559,000
Income tax expense recorded in comprehensive income due to changes in fair value of available for sale securities	5,000	8,000	3,000
Possible reduction in liabilities for uncertain tax positions	2,200,000
Unrecognized tax benefits that, if recognized would affect the effective tax rate	10,600,000
Interest and penalty expense	74,000	30,000	262,000
Accrued interest and penalties	1,800,000	1,900,000
Foreign earnings	63,400,000	40,200,000
Federal [Member]
Schedule Of Income Taxes [Line Items]
Net operating loss carryforwards	22,300,000
Operating losses, expiration beginning date	2021
State [Member]
Schedule Of Income Taxes [Line Items]
Net operating loss carryforwards	200,000
Operating losses, expiration beginning date	2015
Internal Revenue Service (IRS) [Member] | Year One [Member]
Schedule Of Income Taxes [Line Items]
Tax years under examination		2008
Internal Revenue Service (IRS) [Member] | Year Two [Member]
Schedule Of Income Taxes [Line Items]
Tax years under examination		2009
California [Member] | State [Member]
Schedule Of Income Taxes [Line Items]
Tax credits carryforwards	400,000
Credit Subject To Annual Usage Limitations [Member]
Schedule Of Income Taxes [Line Items]
Tax credits carryforwards	$ 100,000